Structures and Properties of Materials Chapter 1
the responses of a material to the application of a magnetic field; common magnetic properties include magnetic susceptibility and magnetization
magnetic properties
designing or engineering the structure of a material to produce a predetermined set of properties
materials engineering
investigating the relationships that exist between the structures and properties of materials (i.e., why materials have their properties)
materials science
relate deformation to an applied load or force; examples include elastic modulus (stiffness), strength, and resistance to fracture.
mechanical properties
Dense, stiff, and strong but ductile ∙ High resistance to fracture ∙ Good conductors of electricity and heat
metals
composed of one or more metallic elements (e.g., iron, aluminum, copper, titanium, gold, nickel), and often also nonmetallic elements (e.g., carbon, nitrogen, oxygen) in relatively small amounts
metals
three categories of solid materials
metals, ceramics, polymers
those that occur in nature; for example, wood, leather, and cork
natural materials
electrons are not bound to particular atoms
nonlocalized electrons
their tendency to soften and/or decompose at modest temperatures, which, in some instances, limits their use
one drawback to polymers
the stimulus is electromagnetic or light radiation; index of refraction and reflectivity are representative optical properties
optical properties
Extremely ductile and pliable ∙ Generally inert and unreactive ∙ Soften at modest temperature
polymers
familiar plastic and rubber materials. Many of them are organic compounds that are chemically based on carbon, hydrogen, and other nonmetallic elements (i.e., O, N, and Si). Furthermore, they have very large molecular structures, often chainlike in nature, that often have a backbone of carbon atoms
polymers
a material trait in terms of the kind and magnitude of response to a specific imposed stimulus
property
has a high degree of perfection, leading to transparency
single crystal
achieve a combination of properties that is not displayed by any single material and also to incorporate the best characteristics of each of the component materials
the design goal of a composite
are related to changes in temperature or temperature gradients across a material; examples of thermal behavior include thermal expansion and heat capacity
thermal properties
naturally occurring materials that are composites
wood and bone
Are definitions of properties independent of shape and size?
yes
Hard, stiff, and strong ∙ Brittle and susceptible to fracture ∙ Good insulators of electricity and heat
ceramics
compounds between metallic and nonmetallic elements; they are most frequently oxides, nitrides, and carbides
ceramics
composed of two (or more) individual materials that come from the categories previously discussed—metals, ceramics, and polymers
composite
Combine other types of materials ∙ Tailor material properties for specific uses ∙ Properties can differ based on fiber direction
composites
relate to the chemical reactivity of materials; for example, corrosion resistance of metals
deteriorative characteristics
capable of large amounts of deformation without fracture
ductile
polymeric materials that display rubbery-like behavior (high degrees of elastic deformation)
elastomers
the stimulus is an applied electric field; typical properties include electrical conductivity and dielectric constant
electrical properties
One of the most common and familiar composites
fiberglass
small glass fibers are embedded within a polymeric material (normally an epoxy or polyester). relatively stiff, strong, and flexible with a low density
fiberglass
typically polymeric materials that have high porosities (contain a large volume fraction of small pores), which are often used for cushions and packaging
foams
what does the structure of a material depend on
how it is processed
